We consider a scenario of 2 point-to-point communication links consisting of 4 nodes operating in the mmWave. We assume that all the nodes are equipped with uniform linear arrays, with transmit antennas placed at half-wavelength. The angle of arrival \(\phi _{i_l}^{n_p,n_c}\)  and angle of departure \(\theta _{i_l}^{n_p,n_c}\)  are chosen to be uniformly distributed in the interval \([-20^{\circ },20^{\circ }]\) . The SI channel is modelled with the Rician factor \(\kappa _{i_l}= 10^{5}\)  dB and the \(r_{m,n}\)  is modelled as in [1]}, with distance between the transmit and receive array of 20 cm and with a relative angle of \(90^{\circ }\) . The number of clusters and the number of paths is set to be \(N_c = 3\)  and \(N_p = 6\) . We define the transmit SNR at node \(i_l\)  as \(\mbox{SNR}_{i_l} = p_{i_l}/\sigma _{i_l}^2\)  and assume it to be the same for all the nodes, denoted as SNR.
We label the proposed hybrid beamforming scheme as HYBF and for comparison purpose, we define the following benchmark schemes
